1. Field of the Invention
This invention relates to sensors useful in aqueous environments such as glucose sensors used in the management of diabetes.
2. Description of Related Art
Sensors are used to monitor a wide variety of compounds in different aqueous environments, including in vivo analytes. The quantitative determination of analytes in body fluids is of great importance in the diagnoses and maintenance of a number of pathological conditions. Illustrative analytes that are commonly monitored in a large number of individuals include glucose, lactate, cholesterol, and bilirubin. The determination of glucose concentrations in body fluids is of particular importance to diabetic individuals, individuals who must frequently check glucose levels in their body fluids to regulate the glucose intake in their diets. The results of such tests can be crucial in determining what, if any, insulin and/or other medication needs to be administered.
Analyte sensors typically include components that convert interactions with analytes into detectable signals that can be correlated with the concentrations of the analyte. For example, some glucose sensors use competitive binding assays, the readout of which is a detectable optical signal. These assays can include components such as glucose binding molecules coupled to elements (e.g. fluorophores) that generate different optical signals in the presence of glucose. Other glucose sensors use amperometric means to monitor glucose in vivo. Such amperometric glucose sensors typically incorporate electrodes coated with the glucose oxidase, an enzyme that catalyzes the reaction between glucose and oxygen to yield gluconic acid and hydrogen peroxide (H2O2). The H2O2 formed in this reaction then alters electrode current to form a detectable signal.
A number of sensors designed for use in aqueous environments are placed into a dry form following their manufacture in order to, for example, facilitate sensor sterilization and/or sensor packaging and/or sensor storage. In this context, methods and materials that facilitate the hydration of such dry sensors in aqueous environments, as well as other characteristics associated with sensor function in such environments, are desirable.